Security systems are known in the art. Often a security guard will monitor an area for a target of interest, such as, for example a person, or automobile in a secure area. Generally, to capture a large area, one would record the secure area using a camera having a large field of view. Additionally, these large field of view cameras are economically viable for such applications due to their cost. However, these wide field of view cameras are often poor in their ability to provide adequate resolution for clearly identifying targets located within the field of view of the camera.
Generally, pan, tilt, zoom cameras are more expensive than the previously mentioned cameras. Pan, tilt zoom cameras are very effective for obtaining close up images of the targets. With these magnified images, security personnel can view these images in great detail and provide a monitoring security function. Unfortunately, if used alone, a single pan, tilt, zoom camera cannot effectively monitor a large and wide field of view of the secured area. If one adds many pan, tilt zoom cameras to view an area, additionally, some targets can be missed if there are not enough pan, tilt, and zoom cameras (hereafter “PTZ cameras”) for an area. This large number of PTZ cameras can also dramatically increase the costs associated with the system. Generally, large field of view cameras, and pan, tilt, zoom cameras are generally difficult to coordinate and control together.
Secondly, images taken by one camera system are generally not immediately compatible with the images taken from a second camera system. Often to zoom on a target object found with a first field of view camera, a second pan, tilt, zoom camera may zoom in on the wrong location, or zoom the image too much so the target is larger than the field of view.
The present invention relates in general to video systems for a security and monitoring application. One embodiment is directed to a camera and a display system. The system provides both a wide angle field of view and a narrower field of view of an environment for monitoring a target. The target can be monitored in the wide angle field of view. Then, the user can obtain an enhanced view of the target using a second camera in an automatic or semi-automatic manner where the two cameras are calibrated in an effective manner. The system has the ability to view a large area within an environment, and also has the ability to focus in on objects or events of interest within the environment. Such capabilities may be useful for a variety of purposes including, but not limited to, surveillance applications.
United States Published Patent Application No. 2006/0028548 A1 to Salivar et al. discloses an immersive camera system and a pan, tilt, zoom camera system with each camera system being coupled to a processor. The two systems can be correlated with one another using a data unit to correct for parallax effects. Data point object positions can be manually noted by orienting the pan, tilt, zoom camera to view the data point object in a center of the pan, tilt, zoom image. The system notes a fixed point in the immersive image where the user clicked while also noting an orientation of the PTZ camera at the time the user clicked.
However, these procedures are time intensive and do not result in reliable calibration of the two systems, with all sets of images, and particularly are deficient when the target is fast moving through the field of view. A two camera system having a more effective calibration is needed.